Microplásticos en Perna perna (Bivalvia: Mytilidae): Evaluación preliminar comparativa de un banco natural y un cultivo suspendido en el Golfo de Cariaco, Venezuela

RESUMEN | La presencia creciente de microplásticos en ambientes marinos representa una amenaza para los organismos filtradores, como los bivalvos, los cuales muestran una capacidad limitada para escapar de la exposición a estos agentes, filtrando fácilmente las partículas de polímeros mediante su alimentación. En este estudio, se analizaron 160 mejillones provenientes de un banco natural y de un cultivo suspendido. Se evaluó su condición fisiológica a partir del índice de condición (IC3) y el rendimiento (R). Los microplásticos se separaron en las muestras para inspección visual usando un microscopio estereoscópico, cuantificando su abundancia y caracterizándolos físicamente. Los mejillones de cultivo mostraron mayores masas totales pero menor condición fisiológica (IC3 = 32,1; R = 4,43) en comparación con los organismos de vida libre (IC3 = 43,9; R = 1,24). Se registró una marcada diferencia en la carga de microplásticos: 315 partículas en el sistema de cultivo, en comparación a 12 partículas en el banco natural. En los grupos predominaron las fibras, siendo significativamente más abundantes en los ejemplares de cultivo. Se observó diferencias significativas en los índices fisiológicos y en la bioacumulación de microplásticos entre ambos grupos (Mann-Whitney U, P<0,05), mientras que se evidenció una correlación negativa entre la abundancia de microplásticos y la condición de los organismos (Spearman Rho, P<0,05). Este hallazgo indica que los sistemas de cultivo pueden actuar como concentradores de microplásticos representando un riesgo potencial para la salud humana y los ecosistemas marinos. ABSTRACT | The growing presence of microplastics in marine environments represents a threat to filter-feeding organisms such as bivalves, which show a limited capacity to avoid exposure to these agents, readily ingesting polymer particles through their feeding. In this study, 160 mussels from a natural bed and a suspended culture were analyzed. Their physiological condition was evaluated through the condition index (CI3) and yield (R). Microplastics were separated from the samples for visual inspection using a stereoscopic microscope, quantifying their abundance and physically characterizing them. Cultured mussels exhibited higher total masses but lower physiological condition (CI3 = 32.1; R = 4.43) compared to wild organisms (CI3 = 43.9; R = 1.24). A marked difference in microplastic load was recorded: 315 particles in animals from the culture system compared with 12 particles in animals from the natural bed. 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